Effectiveness of Changing Dietary Fat on Weight Loss

Overweight and obesity in the United States and other industrialized countries represents a significant and growing health problem. Individuals who are overweight or obese increase their risk of coronary heart disease (CHD), diabetes (T2D), and the metabolic syndrome. Obesity affects both genders and every ethnicity in the United States. The prevalence of obesity in the United States is currently 32.2% in adult men and 35.5% in adult women. The most recent evidence indicates that 33.8% of adults, over 66 million American adults, are obese (30 million men and 36 million women) while an additional 74 million (42 million men and 32 million women) are overweight. The prevalence of obesity has grown a shocking 40% over the last 30 years.

These problems are truly global in nature. In European countries obesity ranges from 20-30% of the population and is even higher in Australia, South America, and Polynesia. The World Health Organization estimates that there will be over 1.5 billion obese individuals worldwide by 2020 if current trends continue.

Calorie controlled diets have routinely been demonstrated to help in both short and long-term weight reduction in individuals who are overweight or obese. In particular, hypocaloric diets, with a calorie reduction of 500 kcals per day have been shown in numerous studies to result in safe and effective weight loss.

It is important for individuals who are following weight loss programs to maintain healthy nutritional patterns, to maintain or improve their dietary quality. Haas avocados can play a significant role as part of a healthy weight loss program and help individuals not only improve their dietary quality, but also lower their risk of chronic diseases such as CHD, T2D, and the metabolic syndrome. Avocados are high in monounsaturated fat, dietary fiber, and a variety of other important phytochemicals such as lutein, vitamin E, niacin and folate. Despite these multiple nutritional benefits, myths exist that avocados may be fattening due to their fat and calorie content and therefore, should be avoided by people trying to lose weight.

The current research trial is designed to compare two energy reduced (hypocaloric) diets. One diet will include one Hass avocado/day, while achieving a 500 kcal/day energy reduction. The other diet will follow a usual American diet pattern, but will also include an energy restriction of 500 kcals/day. Parameters to be explored include weight loss, satiety, dietary quality, changes in body composition and risk factors for chronic disease.